21011512567 has 2 divisors, whose sum is σ = 21011512568. Its totient is φ = 21011512566.

The previous prime is 21011512481. The next prime is 21011512589. The reversal of 21011512567 is 76521511012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21011512567 - 2²³ = 21003123959 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21011512267) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10505756283 + 10505756284.

It is an arithmetic number, because the mean of its divisors is an integer number (10505756284).

Almost surely, 2^21011512567 is an apocalyptic number.

21011512567 is a deficient number, since it is larger than the sum of its proper divisors (1).

21011512567 is an equidigital number, since it uses as much as digits as its factorization.

21011512567 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4200, while the sum is 31.

The spelling of 21011512567 in words is "twenty-one billion, eleven million, five hundred twelve thousand, five hundred sixty-seven".